diff options
Diffstat (limited to 'drivers/regulator/max8649.c')
| -rw-r--r-- | drivers/regulator/max8649.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/drivers/regulator/max8649.c b/drivers/regulator/max8649.c new file mode 100644 index 000000000000..3ebdf698c648 --- /dev/null +++ b/drivers/regulator/max8649.c @@ -0,0 +1,408 @@ +/* + * Regulators driver for Maxim max8649 + * + * Copyright (C) 2009-2010 Marvell International Ltd. + * Haojian Zhuang <haojian.zhuang@marvell.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/platform_device.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/max8649.h> + +#define MAX8649_DCDC_VMIN 750000 /* uV */ +#define MAX8649_DCDC_VMAX 1380000 /* uV */ +#define MAX8649_DCDC_STEP 10000 /* uV */ +#define MAX8649_VOL_MASK 0x3f + +/* Registers */ +#define MAX8649_MODE0 0x00 +#define MAX8649_MODE1 0x01 +#define MAX8649_MODE2 0x02 +#define MAX8649_MODE3 0x03 +#define MAX8649_CONTROL 0x04 +#define MAX8649_SYNC 0x05 +#define MAX8649_RAMP 0x06 +#define MAX8649_CHIP_ID1 0x08 +#define MAX8649_CHIP_ID2 0x09 + +/* Bits */ +#define MAX8649_EN_PD (1 << 7) +#define MAX8649_VID0_PD (1 << 6) +#define MAX8649_VID1_PD (1 << 5) +#define MAX8649_VID_MASK (3 << 5) + +#define MAX8649_FORCE_PWM (1 << 7) +#define MAX8649_SYNC_EXTCLK (1 << 6) + +#define MAX8649_EXT_MASK (3 << 6) + +#define MAX8649_RAMP_MASK (7 << 5) +#define MAX8649_RAMP_DOWN (1 << 1) + +struct max8649_regulator_info { + struct regulator_dev *regulator; + struct i2c_client *i2c; + struct device *dev; + struct mutex io_lock; + + int vol_reg; + unsigned mode:2; /* bit[1:0] = VID1, VID0 */ + unsigned extclk_freq:2; + unsigned extclk:1; + unsigned ramp_timing:3; + unsigned ramp_down:1; +}; + +/* I2C operations */ + +static inline int max8649_read_device(struct i2c_client *i2c, + int reg, int bytes, void *dest) +{ + unsigned char data; + int ret; + + data = (unsigned char)reg; + ret = i2c_master_send(i2c, &data, 1); + if (ret < 0) + return ret; + ret = i2c_master_recv(i2c, dest, bytes); + if (ret < 0) + return ret; + return 0; +} + +static inline int max8649_write_device(struct i2c_client *i2c, + int reg, int bytes, void *src) +{ + unsigned char buf[bytes + 1]; + int ret; + + buf[0] = (unsigned char)reg; + memcpy(&buf[1], src, bytes); + + ret = i2c_master_send(i2c, buf, bytes + 1); + if (ret < 0) + return ret; + return 0; +} + +static int max8649_reg_read(struct i2c_client *i2c, int reg) +{ + struct max8649_regulator_info *info = i2c_get_clientdata(i2c); + unsigned char data; + int ret; + + mutex_lock(&info->io_lock); + ret = max8649_read_device(i2c, reg, 1, &data); + mutex_unlock(&info->io_lock); + + if (ret < 0) + return ret; + return (int)data; +} + +static int max8649_set_bits(struct i2c_client *i2c, int reg, + unsigned char mask, unsigned char data) +{ + struct max8649_regulator_info *info = i2c_get_clientdata(i2c); + unsigned char value; + int ret; + + mutex_lock(&info->io_lock); + ret = max8649_read_device(i2c, reg, 1, &value); + if (ret < 0) + goto out; + value &= ~mask; + value |= data; + ret = max8649_write_device(i2c, reg, 1, &value); +out: + mutex_unlock(&info->io_lock); + return ret; +} + +static inline int check_range(int min_uV, int max_uV) +{ + if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX) + || (min_uV > max_uV)) + return -EINVAL; + return 0; +} + +static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index) +{ + return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP); +} + +static int max8649_get_voltage(struct regulator_dev *rdev) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + unsigned char data; + int ret; + + ret = max8649_reg_read(info->i2c, info->vol_reg); + if (ret < 0) + return ret; + data = (unsigned char)ret & MAX8649_VOL_MASK; + return max8649_list_voltage(rdev, data); +} + +static int max8649_set_voltage(struct regulator_dev *rdev, + int min_uV, int max_uV) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + unsigned char data, mask; + + if (check_range(min_uV, max_uV)) { + dev_err(info->dev, "invalid voltage range (%d, %d) uV\n", + min_uV, max_uV); + return -EINVAL; + } + data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1) + / MAX8649_DCDC_STEP; + mask = MAX8649_VOL_MASK; + + return max8649_set_bits(info->i2c, info->vol_reg, mask, data); +} + +/* EN_PD means pulldown on EN input */ +static int max8649_enable(struct regulator_dev *rdev) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0); +} + +/* + * Applied internal pulldown resistor on EN input pin. + * If pulldown EN pin outside, it would be better. + */ +static int max8649_disable(struct regulator_dev *rdev) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, + MAX8649_EN_PD); +} + +static int max8649_is_enabled(struct regulator_dev *rdev) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + int ret; + + ret = max8649_reg_read(info->i2c, MAX8649_CONTROL); + if (ret < 0) + return ret; + return !((unsigned char)ret & MAX8649_EN_PD); +} + +static int max8649_enable_time(struct regulator_dev *rdev) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + int voltage, rate, ret; + + /* get voltage */ + ret = max8649_reg_read(info->i2c, info->vol_reg); + if (ret < 0) + return ret; + ret &= MAX8649_VOL_MASK; + voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */ + + /* get rate */ + ret = max8649_reg_read(info->i2c, MAX8649_RAMP); + if (ret < 0) + return ret; + ret = (ret & MAX8649_RAMP_MASK) >> 5; + rate = (32 * 1000) >> ret; /* uV/uS */ + + return (voltage / rate); +} + +static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + + switch (mode) { + case REGULATOR_MODE_FAST: + max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM, + MAX8649_FORCE_PWM); + break; + case REGULATOR_MODE_NORMAL: + max8649_set_bits(info->i2c, info->vol_reg, + MAX8649_FORCE_PWM, 0); + break; + default: + return -EINVAL; + } + return 0; +} + +static unsigned int max8649_get_mode(struct regulator_dev *rdev) +{ + struct max8649_regulator_info *info = rdev_get_drvdata(rdev); + int ret; + + ret = max8649_reg_read(info->i2c, info->vol_reg); + if (ret & MAX8649_FORCE_PWM) + return REGULATOR_MODE_FAST; + return REGULATOR_MODE_NORMAL; +} + +static struct regulator_ops max8649_dcdc_ops = { + .set_voltage = max8649_set_voltage, + .get_voltage = max8649_get_voltage, + .list_voltage = max8649_list_voltage, + .enable = max8649_enable, + .disable = max8649_disable, + .is_enabled = max8649_is_enabled, + .enable_time = max8649_enable_time, + .set_mode = max8649_set_mode, + .get_mode = max8649_get_mode, + +}; + +static struct regulator_desc dcdc_desc = { + .name = "max8649", + .ops = &max8649_dcdc_ops, + .type = REGULATOR_VOLTAGE, + .n_voltages = 1 << 6, + .owner = THIS_MODULE, +}; + +static int __devinit max8649_regulator_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max8649_platform_data *pdata = client->dev.platform_data; + struct max8649_regulator_info *info = NULL; + unsigned char data; + int ret; + + info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL); + if (!info) { + dev_err(&client->dev, "No enough memory\n"); + return -ENOMEM; + } + + info->i2c = client; + info->dev = &client->dev; + mutex_init(&info->io_lock); + i2c_set_clientdata(client, info); + + info->mode = pdata->mode; + switch (info->mode) { + case 0: + info->vol_reg = MAX8649_MODE0; + break; + case 1: + info->vol_reg = MAX8649_MODE1; + break; + case 2: + info->vol_reg = MAX8649_MODE2; + break; + case 3: + info->vol_reg = MAX8649_MODE3; + break; + default: + break; + } + + ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1); + if (ret < 0) { + dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n", + ret); + goto out; + } + dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret); + + /* enable VID0 & VID1 */ + max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0); + + /* enable/disable external clock synchronization */ + info->extclk = pdata->extclk; + data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0; + max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data); + if (info->extclk) { + /* set external clock frequency */ + info->extclk_freq = pdata->extclk_freq; + max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK, + info->extclk_freq); + } + + if (pdata->ramp_timing) { + info->ramp_timing = pdata->ramp_timing; + max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK, + info->ramp_timing << 5); + } + + info->ramp_down = pdata->ramp_down; + if (info->ramp_down) { + max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN, + MAX8649_RAMP_DOWN); + } + + info->regulator = regulator_register(&dcdc_desc, &client->dev, + pdata->regulator, info); + if (IS_ERR(info->regulator)) { + dev_err(info->dev, "failed to register regulator %s\n", + dcdc_desc.name); + ret = PTR_ERR(info->regulator); + goto out; + } + + dev_info(info->dev, "Max8649 regulator device is detected.\n"); + return 0; +out: + kfree(info); + return ret; +} + +static int __devexit max8649_regulator_remove(struct i2c_client *client) +{ + struct max8649_regulator_info *info = i2c_get_clientdata(client); + + if (info) { + if (info->regulator) + regulator_unregister(info->regulator); + kfree(info); + } + i2c_set_clientdata(client, NULL); + + return 0; +} + +static const struct i2c_device_id max8649_id[] = { + { "max8649", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max8649_id); + +static struct i2c_driver max8649_driver = { + .probe = max8649_regulator_probe, + .remove = __devexit_p(max8649_regulator_remove), + .driver = { + .name = "max8649", + }, + .id_table = max8649_id, +}; + +static int __init max8649_init(void) +{ + return i2c_add_driver(&max8649_driver); +} +subsys_initcall(max8649_init); + +static void __exit max8649_exit(void) +{ + i2c_del_driver(&max8649_driver); +} +module_exit(max8649_exit); + +/* Module information */ +MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver"); +MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); +MODULE_LICENSE("GPL"); + |